Peak-Inspiratory-Flow-Rate Guided Inhalation Therapy Reduce Severe Exacerbation of COPD

Suboptimal peak inspiratory flow rate: a noticeable risk factor for inhaler concordance in patients with chronic airway diseases

BACKGROUND

Inhaler concordance and the peak inspiratory flow rate (PIFR) are important determinants of treatment effects in patients with chronic airway diseases. Adequate PIFR is required for driving aerosol medication into the lower respiratory tract. However, the relationship between them has not been discussed previously. This study aimed to describe the characteristics of inhaler concordance and PIFR in Chinese patients with chronic airway diseases and discuss the associated variables and the relationship between them.

METHODS

In this single-centre, observational study, a total of 680 patients with chronic airway diseases were enrolled from July 2021 to April 2023. We collected data on the socio-demographic and clinical variables of inhaler concordance using the test of adherence to inhalers (TAI) and PIFR. Multivariate logistic regression was conducted to examine variables related to inhaler concordance and PIFR.

RESULTS

A total of 49.4% of patients had low concordance. Patients with chronic obstructive pulmonary disease (COPD) were more concordant than patients with asthma (mean TAI score: 43.60 vs 41.20; p<0.01), while there was no difference in concordance between the asthma-COPD overlap group and the asthma or COPD group. Suboptimal PIFR (adjusted OR, 1.61; 95% CI 1.04 to 2.51) increased the risk of poor concordance among all patients, while triple therapy (adjusted OR, 0.60; 95% CI 0.35 to 0.86) reduced the risk. A total of 54.9% of patients had suboptimal PIFR. Older age, lower educational level, use of dry powder inhalers and lower forced expiratory volume in 1 s % predicted were significantly correlated with insufficient PIFR. Subgroup analysis revealed a greater proportion of patients with insufficient PIFR during exacerbation than during the stable phase (61.7% vs 43.5%, p<0.001).

CONCLUSION

Inhaler concordance was low, and suboptimal PIFR was a risk factor for poor concordance among Chinese patients with chronic airway diseases. In addition, current inhalation devices may not be suitable, and PIFR reassessment should be considered for patients with COPD during exacerbation.

TRIAL REGISTRATION NUMBER

The study was registered in chictr.org.cn (ChiCTR2100052527) on 31 October 2021.

Aerosol Plumes of Inhalers Used in COPD

INTRODUCTION

The selection of inhaler device is of critical importance in chronic obstructive pulmonary disease (COPD) as the interaction between a patient's inhalation profile and the aerosol characteristics of an inhaler can affect drug delivery and lung deposition. This study assessed the in vitro aerosol characteristics of inhaler devices approved for the treatment of COPD, including a soft mist inhaler (SMI), pressurized metered-dose inhalers (pMDIs), and dry powder inhalers (DPIs).

METHODS

High-speed video recording was used to visualize and measure aerosol velocity and spray duration for nine different inhalers (one SMI, three pMDIs, and five DPIs), each containing dual or triple fixed-dose combinations of long-acting muscarinic receptor antagonists and long-acting β2-agonists, with or without an inhaled corticosteroid. Measurements were taken in triplicate at experimental flow rates of 30, 60, and 90 l/min. Optimal flow rates were defined based on pharmacopoeial testing requirements: 30 l/min for pMDIs and SMIs, and the rate achieving a 4-kPa pressure drop against internal inhaler resistance for DPIs. Comparison of aerosol plumes was based on the experimental flow rates closest to the optimal flow rates.

RESULTS

The Respimat SMI had the slowest plume velocity (0.99 m/s) and longest spray duration (1447 ms) compared with pMDIs (velocity: 3.65-5.09 m/s; duration: 227-270 ms) and DPIs (velocity: 1.43-4.60 m/s; duration: 60-757 ms). With increasing flow rates, SMI aerosol duration was unaffected, but velocity increased (maximum 2.63 m/s), pMDI aerosol velocity and duration were unaffected, and DPI aerosol velocity tended to increase, with a more variable impact on duration.

CONCLUSIONS

Aerosol characteristics (velocity and duration of aerosol plume) vary by inhaler type. Plume velocity was lower and spray duration longer for the SMI compared with pMDIs and DPIs. Increasing experimental flow rate was associated with faster plume velocity for DPIs and the SMI, with no or variable impact on plume duration, whereas pMDI aerosol velocity and duration were unaffected by increasing flow rate.

Respiratory function in healthy long-term meditators: A cross-sectional comparative study

PURPOSE

Respiratory function is thought to improve with long-term meditation. This study aimed to assess respiratory function in a cohort of healthy long-term meditators and non-meditators in Sri Lanka.

METHODS

Respiratory function of healthy, skilled long-term meditators (n = 20) practicing Buddhist meditation consistently >3 years, and age-sex matched non-meditators (n = 20) were assessed by assessing resting respiratory rate, spirometry, breath-holding time and six-minute-walk distance. Data were analyzed with SPSS-23 statistical software.

RESULTS

The long-term meditators; 45% male, mean (SD) total lifetime meditation experience 12.8 (6.5) years, aged 45.8 (8.74) years, BMI 23.68 (2.23) kgm-2, and non-meditators; 45% male, mean (SD) age 45.3 (8.05) years, BMI 23.68 (3.28) kgm-2, were comparable. Long-term meditators had slower resting respiratory rates [mean (SD); 13.35 (1.9) vs. 18.37 (2.31) breaths/minute; p < 0.001], higher peak expiratory flow rates [mean (SD); 9.89 (2.5) vs. 8.22 (2.3) L/s; p = 0.03], and higher inspiratory breath-holding times [mean (SD); 74 (29.84) vs. 53.61 (26.83) seconds, p = 0.038] compared to non-meditators. There was no significant difference in the six-minute-walk distance and estimated maximal oxygen consumption between the two groups.Resting respiratory rate of long-term meditators, showed a significant negative correlation with total lifetime meditation practice in years (r = -0.444, p = 0.049), and the average length of a meditation session per day (r = -0.65, p = 0.002). The long-term meditators with longer duration of retreat participation demonstrated lower resting respiratory rate (r = -0.522, p = 0.018) and higher tidal volumes (r = 0.474, p = 0.04).

CONCLUSIONS

Long-term meditators had significantly slower resting respiratory rates and longer breath-holding times, with better spirometry parameters than non-meditators. Greater practice duration and retreat experience appear to be associated with improved resting respiratory function in long-term meditators.

Evaluation of Peak Inspiratory Flow Rate in Hospitalized Palliative Care Patients with COPD

Dry powder inhalers are an effective yet costly COPD medication-delivery device. Patients must possess a minimum peak inspiratory flow rate (PIFR) for inhaled medication to be properly deposited into the lungs. Hospitalized palliative-care patients with diminished lung function due to advanced COPD may not possess the minimum PIFR (30 L/min) for adequate drug delivery. This study aims to quantify PIFR values for hospitalized palliative-care patients with advanced COPD to evaluate whether these patients meet the minimum PIFR requirements. Hospitalized patients ≥18 years old with a palliative-care consultation were eligible if they had a diagnosis of advanced COPD (GOLD C or D). Patients were excluded if they lacked decision-making capacity or had a positive COVID-19 test within the previous 90 days. Three PIFR values were recorded utilizing the In-Check^TM device, with the highest of the three PIFR attempts being utilized for statistical analysis. Eighteen patients were enrolled, and the mean of the highest PIFR readings was 72.5 L/min (±29 L/min). Post hoc analysis indicated 99.9% power when comparing the average best PIFR to the minimum PIFR (30 L/min) but only 51.4% power when compared to the optimal PIFR (60 L/min). This study found that palliative-care patients possess the minimum PIFR for DPI drug delivery.

High Prevalence of Suboptimal Peak Inspiratory Flow in Hospitalized Patients With COPD: A Real-world Study

For optimal drug delivery, dry powder inhalers (DPIs) depend on the patient's peak inspiratory flow (PIF) and the internal resistance of the device to create turbulent energy and disaggregate the powder. A suboptimal PIF may lead to ineffective drug inhalation into the lungs. Our objective was to report the prevalence of suboptimal PIF in patients with COPD hospitalized for any reason using 1 or more DPIs. In this real-world, observational, single‑site, retrospective study, PIF was measured for each DPI using the In-Check™ DIAL set to match the resistance of the DPI used by each patient. PIFs <60 and <30L/min were considered suboptimal for low to medium-high- and high-resistance DPIs, respectively. At initial hospitalization, the prevalence of suboptimal PIF was 44.6% in 829 patients (mean age, 71.7 years; 56.8% female); 21.2% were measured during admission for a COPD exacerbation. Suboptimal PIF percentages were 61.0% (38.1±9.5L/min [mean±standard deviation (SD)]) across low to medium-high-resistance DPIs and 17.2% (20.7±4.2L/min) for high-resistance DPIs. Overall, 190/829 patients had 1 or more 30-day all-cause readmission with 253 corresponding PIF measurements. For readmissions, suboptimal PIFs were observed in 49.5% (94/190) of patients. Suboptimal PIF percentages were 65.4% (38.4±9.2L/min) for low to medium-high-resistance DPIs and 19.8% (22.4±3.3L/min) for high-resistance DPIs. As the overall prevalence of suboptimal PIFs in hospitalized patients with COPD varied according to the specific internal resistance of the DPI, these findings may have clinical implications for inhaler selection.